1. Field of the Invention
The present invention relates to a mobile device having an audio data playing unit, and more particularly, to a mobile device playing and outputting audio files having various formats.
2. Description of the Related Art
With the development of information technology, the information and communication environment has been rapidly changed. Mobile communication has become an essential part of most businesses. With the expansion of mobile communication services, more diverse functions have been added to mobile devices. Using the mobile device, a user can make a phone call, transmit/receive a message, store data, receive various information services such as weather and stock updates, and others, as well as use Internet services.
Further, since data storage capacities and processing speeds of microcomputers (MICOMs) are gradually increasing, the user can also listen to music using a mobile communication terminal.
Meanwhile, the size of digital image data has been gradually decreasing due to the development of MPEG technology. Accordingly, the small-sized memory used in a portable terminal can store more files.
Also, MP3 technology, which performs audio compression using MPEG technology to produce smaller amounts of digital data, has been used. With the spread of MP3 music, an MP3 player including a unit for storing MP3 data and a unit for playing the stored MP3 data, and a mobile phone equipped with the MP3 player have become widespread. As a result, the user can listen to MP3 music while being mobile.
Further, the user can listen to MP3 music using an MP3 handset included with a mobile communication terminal, the unit for storing MP3 data, and the unit for playing the stored MP3 data.
Various digital audio storage formats, such as WAV (wave), WMA (windows media audio), MIDI (Music Instrument Digital Interface), ra (Real Audio), and others are in use.
FIG. 1 is a block diagram illustrating the features of an apparatus for controlling a sound signal, which is disclosed in Korean Patent Registration No. 469919.
Referring to FIG. 1, an MP3 handset includes an MSM 101 for performing a main control function of a microprocessor, a microphone 103 for inputting a voice signal, a speaker 104 for outputting the voice signal, a codec 102 located between the MSM 101 and the microphone 103 and the speaker 104 for transforming data, a Multi Media Card (MMC) 109 for storing MP3 music data, a MICOM 105 for playing MP3 music data stored in the MMC, a decoder 106 for decoding a digital audio signal of the MP3 music data output from the MICOM 105, a digital to analog converter 107 for converting the decoded digital audio signal into an analog audio signal, and an ear jack 108 to receive ear phones in order to listen to the converted analog audio signal.
An operation of the above-described MP3 handset will be now described.
When a caller speaks into the handset, a voice signal is input through the microphone 103. The input voice signal is coded by the codec 102, and transmitted to the MSM 101. The MSM 101 receives the transmitted voice signal, and then encodes and compresses the received voice signal. The encoded compressed voice signal is transmitted via a transmitter (not shown).
Further, when the caller speaks with another party via the handset, a voice signal received from the other party is decoded and decompressed by the MSM 101. If the decompressed voice signal is transmitted to the codec 102, the codec 102 receives the transmitted voice signal and decodes the received voice signal. The decoded voice signal is output through the speaker 104.
Further, when MP3 music data is played on the MP3 handset, the MICOM 105 reads corresponding music data from the multi media card 109 where the MP3 music data is stored, and transmits a digital audio signal corresponding to the read music data to the decoder 106. Then, the decoder 106 decodes the transmitted digital audio signal. The decoded digital audio signal is converted into an analog audio signal by the D/A converter 107 in order to be output through the audio jack 108. A user of the MP3 handset can listen to MP3 music through earphones (not shown) plugged in the ear jack 108.
Meanwhile, when a background-music function is executed by the user, the user plays MP3 music data, and can simultaneously transmit the played MP3 music data to the other party. At this time, if the MICOM 105 transmits the digital music data read from the multi media card 109 to the decoder 106, the decoder 106 decodes the digital music data and transmits the decoded digital music data to the D/A converter 107. The D/A converter 107 converts MP3 music data transmitted from the decoder 106 to analog music data under the control of the MICOM 105, and transmits the analog music data to the codec 102.
The codec 102 mixes the analog music data transmitted from the D/A converter 107, and the voice signal input via the microphone 103. The mixed analog voice signal is converted into digital data in order to be transmitted via the MSM 101. If the above-described processes are performed in reverse order on the other party's handset, the other party can listen to the transmitted MP3 music while hearing the caller's voice. Therefore, the caller can talk over the handset while listening to MP3 music together with the called party.
In the conventional MP3 handset, the voice signal and a predetermined sound source are mixed by the user's operation in order to provide the mixed voice signal to the other party. However, the user can only listen to one sound source (one format). Methods and apparatuses for simultaneously playing and controlling various formats of sound sources have not been disclosed.
Recently, requests from various consumers to be able to play sound sources of different formats have been increasing. However, it is difficult to enable the conventional MP3 handset to satisfy the requests. Accordingly, a need for a technology that enables the user to freely play and control various formats of sound sources has increased.